Is there a chart somewhere to look up your rear end tag number to see what gears you have and whether or not you have limited slip?

 

I just called my dealer's parts department and read them the tab number. They told me what I had and actually got it right ! I've not seen a chart of sorts but it seems that anybody that sells rear-end parts can easily tell you based on the tag.

Not exactly what you're looking for but hope it helps anyway.

 

The metal tag on the rear diff tells you.

 

Take a look at the tag on the inside of the driver's door frame. You'll see an axle code at the bottom. Here are some of the more common ones:
19=3.55 gears, non limited-slip
18=3.08 gears, non limited-slip
H9=3.55 gears, limited-slip
B6=3.73 gears, limited-slip.

 

That sucks! I have the H9...I was hoping for at least 3.73's!

 

Actually you came out pretty good. Only a few trucks get 3.73s and most of those are reduced by tire size like in the 7700 payload package. Most of the F-150s around don't have the limited slip like you have and many have higher gears (numerically lower) than 3.55.

 

I've got the 3.55 LS rear end and have towed a travel trailer, done some 4x4'ing and spend a lot of windshield time on the highway and I'm very happy with the gearing. Just watch the a$$ end on wet roads, the LS will tend to want to break it loose if you gun it...
Unless you plan to drag race your truck, the gears you've got are great.

 

I was just hoping for lower gearing because I will be towing a 6x12 enclosed trailer and I wanted larger tires and only have the 4.6 I do know about the limited slip on wet pavement though....I had a ranger 4x4 with the limited slip and the 4.0 and it was very touchy....altough it got better with 33's

 

You will also find a tag bolted to the differential of the truck.
Mine has two tags. One says "syth fluid only" and the other has the gear ratio.

 

Guys,

I am new here, so I am probably going to lots of questions to come. I've been reading as much as possible, but some things are better asked.
I can't read the tag on the rear diff to find out the gear ratio I have, but the axle code on the door is 27. Can anyone tell me what I have ?

Steve

2001 F150 Ex 4x4

 

Welcome !!
27= open (non-limited slip) with a 3.31 ratio.
Those tags on the cover are usually gunked up. A good approach is a rag soaked in WD-40 handy during the crawl.

 

I've also tried to figure if mine is the limited slip or the open diff. I can't tell by the tags. One says syn. fluid only, and the other has a bunch of numbers on it. BUT I do know it's a 3.55 axle ratio because it said it on the window sticker when I bought it. Can anyone help me on this?

 

THE AXLE CODE WAS 19. SO IT'S A 3.55 NON-LIMITED SLIP OPEN DIFF. THANKS TO MASHIE BANKS.